The present invention pertains to a rubber bearing with axial damping, which comprises essentially an inner part, an elastomer, which surrounds the inner part in some sections and is connected to same by vulcanization, chambers for a damping agent, a channel carrier with a damping agent channel, and a bearing sleeve accommodating the above-mentioned parts.
A very great variety of designs of rubber bearings are manufactured and frequently used especially in the automobile industry. They are used, e.g., to mount the wheel suspension or as subframe mounts there. Depending on the intended purpose, different requirements are imposed on the damping behavior of the rubber bearings. The damping behavior can be affected both by selecting the materials, especially the elastomer, and by the design embodiment of the bearing.
It has been known that rubber bearings may be designed such that they have chambers for accommodating a damping agent, preferably a hydraulic damping agent. The quenching effect brought about by the mass damping is utilized to achieve a high damping effect. Damping agent channels, which connect the chambers containing damping agent, are provided for this purpose in the bearing, so that the damping agent can circulate between the chambers and cause the quenching effect due to its mass swinging to and fro.
Such a bearing with chambers for the damping agent and with a specially designed damping agent channel is described, e.g., in DE 197 29 290. A channel carrier, in which the damping agent channel connecting the chambers arranged in a radially distributed pattern to one another, is provided in this bearing between the inner part of the bearing and the outer sleeve. The damping behavior of the bearing can be affected by the amount and the type of the damping agent and, of course, by the size of the damping agent chamber. However, the bearing disclosed in this document is designed mainly to affect the damping behavior in the case of forces introduced radially.
However, the axial damping behavior of the bearing plays an important role especially in subframe mounts. It is therefore desirable to design a rubber bearing such that the quenching effect can also be utilized with respect to an axial damping and the damping behavior can be varied.
The object of the present invention is to provide a rubber bearing which can be designed in a variable manner in terms of its axial damping behavior while having a simple design.
According to the invention, a rubber bearing with axial damping is provided comprising a multipart bearing inner part, an elastomer, which surrounds the bearing inner part in some sections and is connected thereto by vulcanization. The bearing has chambers for accommodating a damping agent, a channel carrier with at least one damping agent channel, which makes possible the circulation of the damping agent between the chambers, as well as an essentially cylindrical bearing sleeve, which accommodates the above-mentioned bearing parts. The bearing inner part has a section with increased diameter compared with a middle area of the bearing inner part at the axial ends of the bearing. The channel carrier has chambers for the damping agent and includes an inner sleeve, an elastomer connected to the inner sleeve by vulcanization, and a channel ring, which surrounds the inner sleeve and the elastomer and is likewise connected to same by vulcanization. The channel ring is arranged between the sections of increased diameter of the bearing inner part. At least one groove is milled into the outer contour of the channel ring. The groove forms at least one channel between the channel ring and the bearing sleeve. The chambers formed in the channel carrier as well as the chambers being formed during the mounting of the bearing between the channel part and the sections of increased diameter of the bearing inner part in the vicinity of the axial bearing ends are connected to one another via the channel.
The rubber bearing comprises, in the known manner, a bearing inner part and an elastomer, which surrounds the bearing inner part in some sections and is connected thereto by vulcanization, and it has chambers for receiving a damping agent as well as a damping agent channel which makes possible the circulation of the damping agent between the chambers. The parts of the bearing are accommodated by an essentially cylindrical bearing sleeve. The bearing inner part is made in one piece, as in the other bearings known from the prior art as well. In addition, the bearing inner part has a section each with increased diameter compared with the middle area of the bearing inner part at the axial bearing ends.
A channel carrier with chambers for the damping agent is arranged according to the present invention between the sections of increased diameter of the bearing inner part. This channel carrier comprises an inner sleeve, an elastomer connected to the inner sleeve by vulcanization, and a channel ring, which surrounds the inner sleeve and the elastomer and is likewise connected to them by vulcanization. At least one groove is milled into the outer contour of the channel ring, and the groove forms at least one channel, via which the chambers formed in the channel carrier as well as the chambers being formed during the mounting between the channel carrier and the sections of increased diameter of the bearing inner part are connected to one another.
According to one possible design, the multipart bearing inner part comprises two carrier bodies, one of which forms the entire middle area of the bearing inner part and a section of one axial bearing end, which section joins the middle area and has an increased diameter compared with the middle area. The other carrier body is designed as a ring, which forms the other axial bearing end of the bearing inner part, which end has an expanded diameter. The last carrier body is pushed according to the present invention over the first carrier body forming the middle area of the bearing inner part. Both carrier bodies are surrounded in the area of the axial bearing ends by an elastomer which is connected to them and to an outer ring each by vulcanization.
A shoulder is advantageously provided for the axial fixation of the channel carrier in the rubber bearing thus designed at the carrier body on the part forming the middle area of the bearing inner part in the vicinity of the section of increased diameter.
To mount the bearing in the correct position, the part of the carrier body forming the middle area of the bearing inner part is also provided with a flattened area on its circumferential surface.
The channel for the damping agent extends according to the present invention obliquely or helically on the outer contour of the channel ring. The damping agent channel connects to one another the chambers which are formed during the mounting between the channel carrier and the sections of increased diameter of the bearing inner part. These chambers are formed, axially opposite one another, in the vicinity of the axial bearing ends due to the shape of the bearing inner part and the channel carrier. Damping that acts both radially and axially and can be easily varied by a corresponding shape of the bearing parts is obtained if there is a connection that makes possible the circulation of the damping agent between the chamber or chambers formed in the vicinity of an axial bearing end and the chambers in the channel carrier.
The modular design of the bearing makes it possible in a particularly favorable manner to coordinate the damping behavior of the bearing with the particular intended use. Moreover, by selecting various shapes of the channel carrier provided according to the present invention, it is also possible in a simple manner to obtain a different characteristic. Thus, the outer contour and the inner contour of the channel carrier as well as the elastomer surrounding the inner sleeve and consequently the outer contour of the channel carrier may have a cross section deviating from the circular shape, while its inner contour has an approximately circular cross section. It is thus possible to vary the characteristics of the bearing without changing the shape of the bearing inner part, especially without deviating from the cylindrical shape in the case of the bearing inner part. For example, it is possible without increased manufacturing effort to obtain different characteristics of the bearing in the circumferential direction by means of a square or rectangular shape of the channel carrier cross section. The multipart bearing inner part composed of the carrier bodies may also comprise relatively thin hollow section elements.
On the whole, the present invention provides a bearing design that is characterized by high flexibility in terms of the adaptation of the essential characteristics of the bearing to the particular intended use. This is achieved above all by the modular design of the bearing, but especially by means of the channel carrier, which makes possible a high degree of variability in terms of the radial damping behavior of the bearing due to the shape of its outer contour, on the one hand, and, on the other hand, permits a fine adjustment of the axial damping behavior due to the length of the damping agent channel being variable within broad limits. In addition, the advantages described are obtained with a comparatively simple bearing design.